Browsing by Author "Leontiou, Theodoros"

Now showing items 1-9 of 9

    • Article  

      Axial nucleon and nucleon to Δ form factors and the Goldberger-Treiman relations from lattice QCD 

      Alexandrou, Constantia; Koutsou, Giannis; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2007)
      We evaluate the nucleon axial form factor, GA(q2), and induced pseudoscalar form factor, Gp(q2), as well as the pion-nucleon form factor, GπNN(q2), in lattice QCD. We also evaluate the corresponding nucleon to Δ transition ...
    • Article  

      Erratum: Axial nucleon and nucleon to Δ form factors and the Goldberger-Treiman relations from lattice QCD (Phys. Rev. D (2007) 76 (094511)) 

      Alexandrou, Constantia; Koutsou, Giannis; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2009)
    • Conference Object  

      Importance of closed quark loops for lattice QCD studies of tetraquarks 

      Berlin, J.; Abdel-Rehim, A.; Alexandrou, Constantia; Brida, M. D.; Finkenrath, J.; Gravina, M.; Leontiou, Theodoros; Wagner, M. (Proceedings of Science (PoS), 2016)
      To investigate the light scalar tetraquark candidate a0(980) (quantum numbers JP =0+), a correlation matrix including a variety of two- and four-quark interpolating operators has to be computed. We discuss efficient ...
    • Article  

      N-to-Δ axial transition form factors from lattice QCD 

      Alexandrou, Constantia; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2007)
      We evaluate the N to Δ axial transition form factors in lattice QCD with no dynamical sea quarks, with two degenerate flavors of dynamical Wilson quarks, and using domain wall valence fermions with three flavors of staggered ...
    • Article  

      Novel analysis method for excited states in lattice QCD: The nucleon case 

      Alexandrou, Constantia; Leontiou, Theodoros; Papanicolas, Costas N.; Stiliaris, Efstathios (2015)
      We employ a novel method to analyze Euclidean correlation functions entering the calculation of hadron energies in lattice QCD. The method is based on the sampling of all possible solutions allowed by the spectral decomposition ...
    • Article  

      Nucleon excited states in N f = 2 lattice QCD 

      Alexandrou, Constantia; Korzec, T.; Koutsou, Giannis; Leontiou, Theodoros (2014)
      We investigate the excited states of the nucleon using Nf=2 twisted mass gauge configurations with pion masses in the range of about 270 to 450 MeV and one ensemble of Nf=2 Clover fermions at almost physical pion mass. We ...
    • Article  

      Nucleon structure using lattice QCD 

      Alexandrou, Constantia; Constantinou, Martha; Drach, V.; Hadjiyiannakou, Kyriakos; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis; Leontiou, Theodoros; Vaquero, A. (2013)
      A review of recent nucleon structure calculations within lattice QCD is presented. The nucleon excited states, the axial charge, the isovector momentum fraction and helicity distribution are discussed, assessing the methods ...
    • Conference Object  

      Using a new analysis method to extract excited states in the scalar meson sector 

      Finkenrath, J.; Alexandrou, Constantia; Berlin, J.; Brida, M. D.; Leontiou, Theodoros; Wagner, M. (Proceedings of Science (PoS), 2016)
      We explore a method to extract energy eigenstates, called Athens Model Independent Analysis Scheme (AMIAS), which is an alternative to solving standard Generalized Eigenvalue Problems (GEVP). The method is based on ...
    • Article  

      Δ-baryon electromagnetic form factors in lattice QCD 

      Alexandrou, Constantia; Korzec, T.; Koutsou, Giannis; Leontiou, Theodoros; Lorcé, C.; Negele, J. W.; Pascalutsa, V.; Tsapalis, Antonios; Vanderhaeghen, M. (2009)
      We develop techniques to calculate the four Δ electromagnetic form factors using lattice QCD, with particular emphasis on the subdominant electric quadrupole form factor that probes deformation of the Δ. Results are presented ...